The calendars of the eldest Cambridge kids are about to get a whole lot busier! According to Us Weekly, Prince George, 7, and Princess Charlotte, 5, are likely to spend a lot more time on their most unusual extracurricular activity next year: They're going to attend more royal engagements with their parents, Kate Middleton and Prince William."William and Kate have loved watching Prince George and Princess Charlotte grow and develop over the last year," an inside source told the magazine.